1. Cell Membrane Physiology

2. Cell Membrane Gatekeeper
“Selectively Permeable” – only some things can get in or out

3. Passive Transport NO ENERGY REQUIRED !!!! Diffusion
Movement from HIGH concentration to LOW concentration until equilibrium is reached
Must be SMALL enough to fit through pores (holes)
Must DISSOLVE in FAT
Examples – oxygen, Carbon dioxide

4. Passive Transport A. Diffusion

6. Facilitated Diffusion
Molecules are too big or don’t dissolve in fat
Molecules use a PROTEIN channel in the membrane
Still moves HIGH to LOW concentration

7. B. Facilitated Diffusion

9. OSMOSIS
Facilitated Diffusion of WATER ONLY!

10. Active Transport ENERGY REQUIRED !!! Solute-pumping
BIG THINGS or movement from LOW to HIGH concentration
ATP is used to activate a protein in the membrane
NO PUMP: NO TRANSPORT (very specific)

11. Active Transport A. Solute-pumping

12. BULK TRANSPORT Exocytosis “Exiting the cell”
Golgi packages the stuff into a sac made of phospholipids
Sac fuses with the membrane and spills contents out

13. BULK TRANSPORT ENDOCYTOSIS “Into the cell”
Pushes the membrane in, pinches into a sac, lysosome opens the sac

14. B. Bulk Transport